1. Field of the Invention
The present invention relates generally to a cartridge such as a memory cartridge including a memory card and, more specifically, to thermal control of such a memory card.
2. Discussion of Related Art
Computer memory is often provided in the form of a memory card comprising a substrate with a number of memory dies assembled into packages that are soldered to the substrate. Electrical contacts are provided on the card, usually along an edge of the card so that the card can be inserted into a memory bus of a computer. The memory dies are typically dynamic random access memory (DRAM) memory dies.
In the past, the memory dies themselves were operable at relatively low speeds. These memory dies were also mounted to substrates in a manner wherein relatively long metal interconnects had to be formed in or on the substrates for purposes of accessing the memory dies electrically. The relatively long metal interconnects also inhibited the speed of the memory cards as a whole. The operable speeds of memory cards in the past were typically in the region of about 50 megabits per second (MB/s). Due to the relatively low speeds of the memory dies and the memory cards, relatively little problems were encountered due to overheating of the memory dies or due to excessive electromagnetic radiation from the memory cards.
The speeds at which memory currently operate are typically at least 400 MB/s. Certain computer memory cards such as the proposed Direct Rambus.TM. DRAM (Direct RDRAM) memory currently operate at speeds of 1.6 gigabits per second (GB/s).
One advancement in memory cards is the mounting of memory dies on a substrate in what is generally referred to in the art as a "chip scale package". In a chip scale package, memory dies are mounted to a substrate by an array of solder balls known in the art as a "micro-ball grid array". A micro-ball grid array generally allows for memory dies to be assembled in packages by being mounted to a die substrate over an area of the die substrate which is less than 1.2 times the area of the individual memory dies. Such packages, in turn, allow for closer positioning of the memory dies to one another, typically in an area which is less than 1.2 times the combined areas of the respective memory dies. By closely spacing the memory dies relative to one another, relatively short interconnects are formed in or on the substrates for purposes of accessing the memory dies electrically. By shortening the interconnects, data transactions can generally be transmitted to and from the memory dies at faster speeds.
The higher speeds at which memory operates have also come with certain penalties. In particular, memory cards are more prone to overheating than in the past. Memory cards also emit more electromagnetic radiation to surrounding areas than in the past, which could affect the electrical performance of computer components which are located in an area near the memory cards.